require 'luacov'
local function withbuf(lines, f)
  vim.go.swapfile = false

  vim.cmd.new()
  vim.api.nvim_buf_set_lines(0, 0, -1, false, lines)
  local ok, result = pcall(f)
  vim.cmd.bdelete { bang = true }
  if not ok then error(result) end
end
return withbuf